The present invention relates to a furnace in which one or more burners fire into a furnace to heat a melt and the material used in forming the melt is loaded into the furnace through adjacent charge wells. More particularly, the present invention relates to such a furnace in which flue gases produced within the furnace are directed onto material loaded into the charge wells through openings defined in the sidewalls of the furnace.
Many industrial processes require material such as scrap metal to be melted within furnaces. Oxy-fuel burners such as disclosed in U.S. Pat. No. 5,299,929 have been advantageously used to deflect flames over the material to be melted within the furnace.
A known furnace design utilizes sidewalls to form an enclosure to contain a melt. One or more burners fire into the furnace to maintain the melt and one or more adjacent charge wells are proved to load material to be melted into the furnace. Submerged openings, also known as submerged arches, are provided to circulate melt to the charge wells, thereby to help melt the material used in forming the melt and to recirculate melted material back to the furnace. Submerged pumps are used to effect the required circulation of melted material to and from the charge wells to the main melting chamber of the furnace.
In any furnace, it is important that the combustion take place in the most thermally efficient manner in order to conserve both fuel and oxidant. However, in conventional furnaces such as described above, there are heat losses due to flue gases being vented from the furnace. Flue gases as known in the art are heated gases made up of the furnace atmosphere which can include combustion products and any volatiles evolved from the melt. As will be discussed, the present invention provides improvement to furnaces such as outlined above by utilizing the flue gases in a thermally efficient manner.